.body{
	background-color: #21202D;
}

.container {
	width: 500px;
	height: 50px;
	margin: 100px auto;
}
	
.parent {
	width: 100%;
	height: 42px;
	top: 4px;
	position: relative;
}
	
.parent>input:first-of-type {
	/*输入框高度设置为40px, border占据2px，总高度为42px*/
	width: 380px;
	height: 40px; 
	border: 1px solid #ccc;
	font-size: 16px;
	outline: none;
}

.parent>input:first-of-type:focus {
	border: 1px solid #317ef3;
	padding-left: 10px;
}
	
.parent>input:last-of-type {
	/*button按钮border并不占据外围大小，设置高度42px*/
	width: 100px;
	height: 44px; 
	position: absolute;
	background: #317ef3;
	border: 1px solid #317ef3;
	color: #fff;
	font-size: 16px;
	outline: none;
}